使用数据库完成简单的修改密码功能

// 修改密码确定
            updata_newpass = et_updata_newpass.getText().toString();// 新密码
            updata_oldpass = et_updata_oldpass.getText().toString();// 新密码
            updata_user = et_updata_user.getText().toString();// 新密码
            Cursor cursor_getuser = db.rawQuery(
                    "select * from user where username = ?",
                    new String[] { updata_user });// 新建数据库指针
            if (updata_user.equals("")) {// 用户名为空
                DiyToast.showToast(LoginActivity.this, "请输入用户名");
            } else if (updata_oldpass.equals("")) {// 旧密码为空
                DiyToast.showToast(LoginActivity.this, "请输入旧密码");
            } else if (updata_newpass.equals("")) {// 新密码为空
                DiyToast.showToast(LoginActivity.this, "请输入新密码");
            } else {
                if (cursor_getuser.moveToNext()) {
                    Cursor cursor_getoldpass = db.rawQuery(
                            "select * from user where username = ?",
                            new String[] { updata_user });
                    cursor_getoldpass.moveToFirst();
                    String oldpass = cursor_getoldpass
                            .getString(cursor_getoldpass
                                    .getColumnIndex("passward"));
                    if (updata_oldpass.equals(oldpass)) {
                        if (updata_newpass.equals(updata_oldpass)) {
                            DiyToast.showToast(LoginActivity.this, "新旧密码不能一致！");
                        } else {
                            db.execSQL(
                                    "update user set passward = ? where username = ?",
                                    new String[] { updata_newpass, updata_user });// 更新数据库
                            DiyToast.showToast(LoginActivity.this, "修改密码成功");
                            line_login.setVisibility(View.VISIBLE);
                            line_reg.setVisibility(View.GONE);
                            line_updata_pass.setVisibility(View.GONE);
                        }
                    } else {
                        DiyToast.showToast(LoginActivity.this, "旧密码输入错误");
                    }
                } else {
                    DiyToast.showToast(LoginActivity.this, "用户名错误");
                }
            }